Bushing and method of forming the same



192 Aug 7 B. J. GUDGE BUSHING AND METHOD OF FORMING THE SAME 2Sheets-Sheet 1 Filed Nov. 28, 1919 3 INVENTOR Be/y'amim/ 621 6WITNESSES:

ATTbRNEY I 1,640,543 v 1927' B. J. GUDGE BUSHING AND METHQD OF FORMINGTHE SAME Filed Nov. 28, 1919 2 Sheets-Sheet 2 I I?! m m x m WITNESSES:INVENTOR 1 I ATTORNEY 'IBENJ'AMIN J. GUDGE, OF WILKINSBURG,

PATIENT OFFICE.

PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURINGCOMPANY, A CORPORATION OF PENNSYL- VANIA.

BUSHING AND METHOD OF FORMING THE SAME.

Application filed November 28, 1919. Serial No. 341,606.

My invention relates to bushings and to methodsof manufacturing them andit has, for its primary object, the provision of an insulating bushingformed with an integral been satisfactory for some purposes.

flange in such manner as to ensure a strong structure throughout and,particularly, at the juncture of the body portion and the flange. I

One of the objects of my invention resides in constructing a bushing ofthe above mentioned character from superimposed layers of fibrous sheetmaterial, such as paper,

cloth, duck and thelike impregnated with a binder which will give thefinished product the requisite strength, permanency of form andinsulating qualities. Various binders, such as shellac, phenoliccondensation products, copal, casein and like shellac substitutes may beemployed but I prefer to employ a binder which may be hardened byapplication of heat and pressure, such as bakelite.

Various methods have been practiced in the manufacture of bushings fromsheet material and a binder. and such bushings have For example, byonemethod, a-tubular body, comprising superimposed convolutions offibrous sheet material associated with a proper binder, has beendisposed about a cylindrical mandrel with one end of the convolutions inengagement against one of a plurality of annular sheets of similarmaterial superimposed upon the bottom plate of the mold, and moldelements have been assembled about the sheet material thus disposed tocompact it and harden the binder. The result has been an insulatingbushing comprising a tubular body portion havinganintegral outwardlydirected flange at one end. This bushing has possessed the desiredinsulating properties but has been mechanically weak at the juncture ofthe tubular portion of the bushing and its flange.

Another method, which has been practiced with somewhat more success, comrised superimposing'a plurality of discs of brous sheet materialassociated with a binder and provided centrall with slits about acylindrical mandrel orced through the slitted portions of the discs. Thediscs and mandrel were then disposed upon the bottom portion of amold,the tubular body portion of superimposed layersof similar sheetmaterial treated with a binder was placed about the mandrel and thematerial thus assembled was subjected to heatand pressure through theemployment of suitable molding elements to compact the material andharden the binder. By this method, a somewhat stronger structure at thejoint of the tubular body portion and *flange of the bushing wasproduced. However, this jointhas been found to betoo weak in someinstances and is also liable to be too bulky.

, With these ditfic'ulties in View, my present invention comprehends theprovision of a method of forming flangedbushings by which an extremelystrong and compact joint is formed between the bushing proper and itsflange so .that all parts of the bushing possess substantially-uniformstrength and thickness. j

A still further object of my invention comprises a method ofmanufacturing bushings of the foregoing character which may be simplyandrapidly practiced and which will not requlre any unusual skill uponthe part of the operators. V

With these and other objects in view, Fig.

1 is a perspective View of a'bushin which may be constructed by thepractice 0 my invention; Fig. 2 is a plan view of a mold which may beemployed in forming a bushing, showing a bushing in plate; Fig. 3 is asectional view of the mold and its enclosed bushing, taken along theline 33 of Fig. 2, Fig. 4 ,is a plan View, parts being broken away forthe sake of-clearness, illustrating the method of assembling the fibroussheet material according to my invention, Fig. 5 is a plan view of astrip of material slitted in accordance with my'invention, and Fig. 6 isan exploded view of thebushing shown in Fig. 1. r i

In Fig. 1 of the drawing, I have illustrated a bushing, constructed inaccordance with my invention, which may comprise a tubular body portion1 formed, at one end, with a laterally directed peripheral'flange 2. Thetubular body portion 1 may be cylindrical in form but it preferablytapers slightly from its flanged end, when the use to whichit is to beput will permit it, in order to facilitate the molding operation.

In order to ensure a .clear and accurate understanding of my inventionand the method of practicing it, a general knowledge of a mold suitablefor forming the bushing is essential, and reference is, therei fore, toFigs. 2 and 3 of the draw-' Bastian, Se t. 8, 1919, Serial 'No. 322,542,

I strength.

and assigns to the Westinghouse Electric & Manufacturing Company andrelating to molds.

Briefly stated, a mold suitable for, em-

ployment in the practice of my inventionmay comprise an annular bottomplate 3, the central opening of which may snugly receive the enlargedlower end 4; of acentering pin or mandrel 5.. This centering pin ormandrel ma cross-section and may taper slightly towards its up er end.(Jo-operating with the bottom p ate and centering pin are three or moresplits 6, so formed that, when assembled about the centering pin, withtheir opposed faces abutting each other, they provide a substantiallyfrusto-conical body forming a continuation of the peripheral wall of thebottom plate, which is correspondingly inclined. A matrix or press ring7 1s provided having its inner face inclined to engage uniformly againstthe inclined outer faces of the splits and bottom plate so that, when itis lowered about the upper portions of the splits and forced downwardlyto the position shown in Fig, 3, it will force the splits inwardl 7 anddownwardly against material dispose between them and the mandrel andbottom plate to uniformly and strongly compact the material.

My present invention comprises animproved method of shaping and fittingfibrous sheet material, of any desired character .and associated withany suitable binder, in such manner that it may be disposed within amold of the character above described and there subjected to pressureand such other treatment as may be required to compact the material andharden the binder to produce a body havin the desired permanency ofshape and While various binders may employed and diflerent sheetmaterialsmay be utilized, I prefer to form bushings :from cotton duckwhich has been impregnated 'with a phenolic b condensation product insolution and'from which all solvent has been driven-in such manner as toleave the binder in a solid but moldable condition. In otherwords, whenexpelling the solvent, care should be taken that the temperature doesnot reach such a point as to convert the binder to its final solid andsubstantially insoluble and infusible condition. I

Sheet material so treated may be cut to ,E id a strip equal in width tothe comined length of the body portion of the uniformity of bushing andthe radial dimension of the flange, and the strip thus provided may beslitted at suitable intervals, along and at right angles to its longeredges, to provide a plurality of tongues equal in length to the radiusof the flange. Additional sheet material may be cut to provide aplurality of annular layers of the external diameter of the desiredbushing flange and having central openings of diameters varying fromthat of the internal diameter of the desired bushing to a diameter butslightly less than that of the desired flange. Obviously, the.

preparation of the slitted sheet and of the several annular layers maybe performed by 'unskilled labor. preferably be of circular 4 WVith thematerial thus prepared, the bushing bod may be assembled by winding theslitted s eet to form a tubular body 8 of superimposed layers of.treated material, reference being had to Fig. 4 of the drawings. Thetongues '9 formed at the slitted edge of the sheet,so wound, may be bentoutwardly, and each layer of tongues arranged. alternately to cover theopenings between the tongues in the previous layer, as shown and may bedisposed upon an annular bottom sheet 10 having the mternal diameter ofthe corresponding diameter of the. desired bushing. A plurality ofannular layers 11 of l graduated width may then be concentricallydisposed'in superimposed relation upon the laterally projecting tongues9, after which a top layer 12, having a central opening fitting snnglyabout the tubular portion 8, may be applied. The snug engagement of thetubular portion 8 in the opening of the top layer 12 serves to preventdisplacement of any of the various layers and also prevents the tubularportion 8 from becoming unwound. B interposing a suitable number of theintermediate layers 11 of proper graduated widths, I provide additionalmaterial, to compensate for the shortage of material in the outerportion of the flange, so that a flange of substantially uniformthickness of material is provided. I

\Vhen ,the bushing body has been as,- sembled, as above described, thetubular portion ma be slipped over the centering pin 5 of a mo d untilthe flan e portion rests upon the bottom plate '3. T e s lits 6 may thene positioned about the tu ular portion of the bushing and in engagementwith the upper layer 12 of the flange portion thereof, and the matrix 7of the mold, may be lowered about the upper portions of the s lits. Theassembled mold, with the cue osed bushing, may then be disposed in'asuitabl heated ress which may be actuated to simu taneous y heatthevarious mold sections and to force the matrix 7 downwardly to theposition shown in Fig. 3 ofthe drawings. The movement of .the matrixforces the splits inwardly and downwardly to strongly and lUU mandrelthereof. The combination of heat uniformly compact the superimposedlayers of fibrous material, both against the bottom of the mold andagainst the centerlng pin or and pressure thus provided will firstsoftenand then harden the binder of the sheet ma- 'te1 'ial,if a phenoliccondensation product I or other adhesive hardeningupon the applicationof heat is employed.

By practicing my invention. as above set forth, I obtain a bushing ofthe desired permanency of form and insulating qualities which,furthermore, possesses an unusual and 'highly desirable degree ofstrength. The

strength obtained may be attributed to the factthat the-tongues .9,whichare integral I with the sheet material forming the bodyof the mold,project laterally to the outer ."edge of the bushing flange and arelocked firmly between the several layers compflis- I ing the mainportion of the flange.

- combined with the fact that the graduated intermediate layers ensure asubstantially uniform thickness of material throughout the width of theflange, ensures not only a strong flange but a strong joint between theflange and body of the bushing.- Furthermore, there is no unduethickening of the material about the joint as has been the case thepast.

,While I'have described my invention in considerable detail, it will beappreciated that it is susceptible of various modifications. Forexample, the opposite end of the, sheet forming thebo-dy of the bushingmay be slitted to provide tongues, and a second flange may be formed, inidentically the same manner as the first, at the'other end of thebushing. As this is merely a dupli cation of the method above describedand as n the application of A. J. Bastian. hereinbefore referred to,discloses amold suitable for forming a bushing with flanges at both'ends, any further description orzillustration of this modification of mypresent case is believed to'be unnecessary.

Although I have disclosed a preferred embodiment of my invention, itwill, of course, be appreciated that I reserve the right'to.

make any changes, both in the materials employed and in the methodpracticed in assembling and treating them, which may come within thescope of the claims or which the prior art will permit.

I claim as my invention 1. Thegnethod of forming flanged tubular objectsthat comprises forming a tubular body of moldable material withoutwardly projecting-portions, disposing moldable material against theprojecting portions and molding the material thus assembled to compactand harden it into a tubular structure provided with a flange formed bythe proecting portions of the tubular body and the materlal disposedagainst them.

. 2. The method of forming flanged tubular objects that comprisesforming a tubular body of fibrous sheet material, associated with abinder and provided with integral outwardly projecting portions,disposing 7 fibrous sheet material impregnated with a binder against theoutwardly projecting portions and treating the body thus assembled tocompact the material and to harden the binder.

3. The method of forming flanged tubular objects that comprises forminga tubular body portion of fibroussheet material associated with a binderand provided, at one end, with outwardly directed radial tongues,

impregnated with a like binder against the opposite faces of the tonguesand subject ing the entire body thus assembled to heat and pressure in amold to compact it and harden its binder. I

v 5. The method of forming flanged tubular objects that comprisesproviding slits in one edge of a sheet of fibrous material impregnatedwith a binder to provide a series of tongues, winding the sheet toprovide a tubular body comprising a plurality of superimposedconvolutions, bending the tongues outwardly with respect to the body,disposing aplurality of annular layers of sheet ma terial impregnatedwith a binder. against the opposite faces of the tongues and treatingthe body thus assembled under pressure in a mold to compact it andharden its binder.

6-. The method of forming flanged tubular objects that comprises forminga tubular body of superimposed layers of fibrous sheet materialimpregnated with a binder and provided, at one end, with outwardlydirected,

integral tongues, disposing a plurality of annular layers of fibroussheet material impregnated with a binder against the faces of thetongues, all of the layers being of uniform, external diameter andcertain of the layers being of graduated internal di-v ameter and.treating the material thus assembled in a mold the binder.

7. A flanged tubular object comprising a to compact it and harden.

tubular body of superimposed/ layers of fibrous'material provided, atone end, with outwardly directed integral tongues and annular layers offibrous sheet material disposed against the faces of the tongues forco-o erationtherewith' to form a flange, all of t e la *jers beingassociated with a hard.- ened bin er.

8. A flaned tubular object comprising a tubular b0 y of superimposedlayers of fibrous material provided, at one end, with outwardly directedintegral tongues andannular layers of fibrous sheet material disposedagainst the faces of the tongues for (lo-operation therewith to form aflan e, all

. of the sheet material being impregnate with a heat hardened binder.

9. A fian ed tubular object comprising a tubular body of su rimposedlayers of fibrous material provided, at one end, with outwardly directedintegral tongues and annular layers of fibrous sheet material disposedagainst the faces of the tongues for 00- operationtherewith to form aflange, all of the layers being impregnated with a hardened phenoliccondensation product.

1n testimony whereof. I have hereunto subscribed my name this 21st dayof November, 1919,

BENJAMIN J. GUDGE,

